Portal: What is your favourite part?

[Kratos]

So i just finished Portal and its awesome. Just love it.

But what was the funniest part of the game? What was the most coolest part? And best gameplay part.

Funniest: Portal Song: Still Alive, and you will get cake.

Coolest: 'The cake is a lie' room. Reminds me of a good old thriller.

Gameplay: Room 18, really difficult but awesome, and the escape is awesome as well.

What do you think of this game?